Industrial gasses are conventionally supplied in cylinders at up to 200 bar. More recently cylinders have been designed which can accommodate gas in excess of 300 bar. Although there are considerable advantages in using the new cylinders many customers do not have pressure regulators capable of handling pressures above 200 bar.
Pressure reducing valves capable of reducing pressure from 300 bar to 200 bar are well known and it would be possible to provide customers with cylinders reducing valve. This would avoid the necessity for the customer to buy new pressure reducing valves. However, the refilling of such cylinders would entail removing the pressure reducing valve, filling the cylinder through the conventional cylinder valve, closing the conventional cylinder valve and refitting the pressure reducing valve. This is a time consuming operation.